Advancements in Electrolytes: From Liquid to Solid for Low‐Cost and High‐Energy‐Density Micro‐Sized Silicon‐Based Batteries

This review systematically examines advancements in electrolytes from liquid to solid-state systems for micro-sized silicon (µSi)-based anodes in LIBs. Distinct compositional variations, challenges, and breakthroughs across these systems are analyzed, focusing on their roles in addressing µSi anode volume expansion and interfacial instability. Tailored optimization strategies for liquid, quasi-solid, and all-solid-state electrolytes highlight pathways toward advancing high-energy-density µSi-based battery technologies.

Abstract

Silicon has emerged as a pivotal candidate for next-generation high-energy-density lithium-ion batteries (LIBs) due to high specific capacity (3579 mAh·g⁻¹), natural abundance, and cost-effectiveness. Compared to nano-Si, micro-sized silicon (µSi) anodes have historically struggled with significant challenges owing to more severe volume expansion. However, µSi has recently regained substantial research attention owing to superior tap density and lower production costs. Electrolytes are pivotal in alleviating volume expansion and stabilizing the electrode-electrolyte interface, making their tailored design indispensable for addressing the inherent challenges of µSi anodes from liquid to solid-state systems. This review first examines the intrinsic challenges confronting µSi anodes and their corresponding electrolytes, proposing targeted design principles. Subsequently, recent advancements and optimization strategies from liquid to all-solid-state electrolytes in µSi anode systems are comprehensively summarized. In contrast to liquid electrolytes, research on solid-state electrolytes remains limited and faces more pronounced challenges. Finally, the development prospects of different electrolyte systems for µSi anodes are critically discussed, outlining persistent challenges and proposingcomprehensive countermeasures. This review delivers insightful perspectives for accelerating the commercialization of µSi anodes in high-energy-density LIBs, while also serving as a valuable reference for advancing other micro-sized anode material systems.